Obscured by Clouds. The rough and ready blog of a cloud benighted biologist and amateur astronomer. Astroblog will cover my interests in astronomy, biology and Life, the Universe and Everything.

Tuesday, July 19, 2016

The Sky This Week - Thursday July 21 to Thursday July 28

The Last Quarter Moon is Wednesday July 27. Venus and Mercury rise in the early evening sky. Jupiter
is visible in the early
evening.
Mars and Saturn are visible all evening long. Saturn is close to the red
star Antares and forms a triangle
with Mars.
Comet C/2013 X1 PanSTARRS may be visible in strong binoculars
in the evening sky.

The Last Quarter Moon is Wednesday July 27. The Moon is at perigee, when it is closest to the Earth, on the 27th.

Evening sky on Saturday July 23 looking west at 30 minutes after sunset.
Jupiter is above Venus and Mercury, forming a line with the star Regulus. Similar views
will be seen throughout Australia at the equivalent local time. (click
to embiggen).

Jupiterwas
at opposition on the March 8th, when it was biggest and brightest as seen from
Earth. Jupiter will be an excellent telescopic target but s rapidly coming too close to the horizon.

Jupiter is in
the north-western evening sky as the sun sets, and is
good for telescopic observation from around 18:00 on until around 9:00
pm
when it will be a little too close to the horizon. Jupiter's Moons
will be an still be excellent sight.

Venus and Mercury continue to rise above the twilight glow this week, you will need a
clear, unobstructed horizon to see them effectively at the beginning of the week, but by the end of the week Mercury will be sufficiently high in the dusk sky to see clearly. A little after half an hour after sunset, Venus, Mercury, the bright star Regulus and Jupiter make a nice line-up in the dusk sky.

Evening sky on Saturday July 23 looking west as seen from
Adelaide
at 22:00 ACST. Mars, Saturn and Antares form a triangle. The
inset shows telescopic views of Mars and Saturn. Similar views
will be seen elsewhere in Australia at the equivalent local time. (click
to embiggen).

Mars
is high in the evening skies near the head of the Scorpion in Libra.

Mars continues to head back towards the head of the Scorpion this week.
Mars forms a line with the
star Dschubba in the head of the Scorpion and Antares. As well Mars
forms a triangle with Saturn and the
red star Antares. Mars was at opposition on May 22, and is visibly dimming,
but is still a decent telescope object. It is visible all evening
long. In even small telescopes Mars will be a visible disk, and you
should see its markings.

Saturn was at opposition on the 3rd of June. However, Saturn's change in size and brightness is nowhere
near as spectacular as Mars's, and Saturn will be a reasonable
telescopic object for many weeks. Saturn is reasonably high in the evening sky and
is readily visible below
Scorpius. Saturn forms a triangle with Mars and the red star
Antares. It is now high enough for good telescopic observation in the
evening. In even small telescopes its distinctive rings are obvious.

Comet C/2013 X1 (PANSTARRS)
rises around 4:00 pm local time, and is clear the of horizon
murk from around 7:30 pm. It is
currently around magnitude 7.5, by the end of the week the waning Moon will rise sufficiently late that there is good chance of seeing the comet before Moon rise in good binoculars. The comet will be close Centaurus for much of this week.
Detailed maps and guides are here.

There are lots
of interesting things in the sky to view with a telescope. If you don't
have a telescope, now
is a good time to visit one of your local astronomical societies open nights or the local planetariums.